Object PHOSPHORUS.msl

// ---------------------------------------------------------------------------
//  HEMMIS - Ghent University, BIOMATH - Université Laval, modelEAU
//  Implementation: Peter Vanrolleghem, Frederik De Laender, Ludiwine Clouzot.
//  Description: MSL-USER/ELAFish
// ---------------------------------------------------------------------------

#ifndef OBJECTPHOSPHORUS
#define OBJECTPHOSPHORUS


CLASS PHOSPHORUS (* class = "detritus" *) EXTENDS NITROGEN WITH
 {:
 interface <- 
 { 
 OBJ  Assimilation_PO4 (* terminal = "in_3" *) "PO4 assimilated by algae": RateProcess := {: causality <- "CIN" :}; 
 OBJ  Phosphate_in (* terminal = "in_4" *) "": RateProcess := {: causality <- "CIN" :}; 
 OBJ  Phosphorus_out (* terminal = "out_1" *)"": Concentration := {: causality <- "COUT" :};
 OBJ  Phosphate_out (* terminal = "out_1" *)"": Concentration := {: causality <- "COUT" :};
  };
 
 parameters <-{};
 
 independent <- { };
 
 state <-
 {
 OBJ  Phosphate"" : Concentration;
 OBJ MIX_Phosphate "mixing rate of Phosphate": RateProcess;
 OBJ AccMix_Pin "Accumulation of mixing Phosphate entering": Real; 
 OBJ AccMix_Pout "Accumulation of mixing Phosphate exiting": Real;
 };
 
 equations <-
 {
 DERIV(state.Phosphate,[independent.t])= (state.DECOMP_DD + state.DECOMP_PD + state.DECOMP_SD + interface.RESPIRATION_algae + interface.RESPIRATION_animals + interface.EXCRETION_animals) * parameters.P2OM - interface.Assimilation_PO4 + state.MIX_Phosphate;
 state.MIX_Phosphate = IF ((fabs(parameters.Temperature - parameters.T_strat) > 3) && (parameters.Temperature > 4)) 
 			  	   	   	  THEN 0
				  		  ELSE parameters.QMix * (interface.Phosphate_in - state.Phosphate) / parameters.VTot;
				   
 DERIV(state.AccMix_Pin,[independent.t]) = IF ((interface.Phosphate_in - state.Phosphate) < 0)
 			  	   						  	    THEN 0
				   							    ELSE state.MIX_Phosphate;
 
 DERIV(state.AccMix_Pout,[independent.t]) = IF ((interface.Phosphate_in - state.Phosphate) > 0)
 			  	   						  	 	THEN 0
				   							 	ELSE state.MIX_Phosphate;
																   
 interface.Phosphorus_out = state.Phosphate;
 
 interface.Phosphate_out = state.Phosphate;
 
 //there is only one form of P and that is PO4, expressed as PO4-P, so in this case PO4 = P
 
 };
 
 :};

 #endif